When handling cargo hanging in a hook, there often are claims concerning security to prevent that cargo unintentional will is released from the hook. In the offshore field, a critical point when handling hanging cargo in the air from and from deck and specially in the “splash zone”, where the cargo specially is exposed to be released by the waves and vessel movements, under which specified assumptions, are able to “lift” the cargo and influence traditional security units for heavy load and risk.
In addition will fast and reliable on- and offloading of cargo gives considerable reduce use of time during so called “critical lifting phase” as for example; time spent from time point when “installed cargo”, to time point for “released installed cargo”. This is phase or time which is tried to reduce to 3 minimum because of high risk, special when weather condition in the ocean surface is challenging for the ships position.
Concerning offshore oil industry, lift of cargo are done in surroundings which requires special claims for equipment in use. The mix of different elements and a sharply reduced visual control, which requires that claims to correct and secure operational function of the equipment is very high. For underwater operations, will also on and off handling the cargo of the hook be done by the ROV which limited suppleness and maneuverability.
This industry have therefor, in cooperation with the national authority, defined a number of guidelines for secure operational handling, during different such functional handling. For lifting equipment or hooks, the industry defines that the hook with sufficient security shall have two different locking mechanisms or security units. At least one of those shall have respectively a vertical and a horizontal movement according to each other.
In Norwegian oil industry are guidelines made of the industry organizations; IMCA and NORSOK GUIDELINES, which is normative for the industry in its whole.
They are lifting equipment which already satisfies these guidelines, but as a common they are complicated, expensive to produce and very consuming to operate. To reduce the price at a properly approved end equivalent equipment, is obviously competitive advantage.
It is also very important to be able to contribute reduce the operation time for the operator. In majority of all underwater operations there is enormously resource intensive to do these operations. The industry is searching tirelessly for new functions, procedures and/or innovative equipment which can contribute to reduce operational time. Our securing mechanism is very simple and fast to operate relative to other known 2-steps locking mechanisms. This will be a big competitive advantage.
Already known technical solutions for example: WO-2013040637-A1 where an extra safety device can be added to a standard shaft type of lifting hook. The extra safety device locks the original hook safety lip so it is prevented from being opened un-intentionally. The safety gate requires to be operated by either divers or ROV.
U.S. Pat. No. 219,677 and U.S. Pat. No. 2,603,524 describes a sliding arrangement to prevent load to unhook itself. The sliding movement, is secured by a locking likely unit.
Another known technic is: U.S. Pat. Nos. 2,866,247, 4,539,732 and GB-1.032.584 where a pivoting Sip closes the hook gate to prevent the load unhooking itself,
None of these safety mechanics, except, WO-2013040637-A1, can be fitted to a standard long shank hook and none of these arrangements, add an extra safety latch to the hook, which is a demand from the oil industry.